Heart Rate Zone Calculator
Calculate your 5 personalised heart rate training zones using the Karvonen formula. Enter your age and resting heart rate to get exact BPM targets for each zone.
Understanding the 5 Heart Rate Zones
The Karvonen formula calculates target heart rate based on your Heart Rate Reserve (HRR = Max HR − Resting HR). This method is more personalised than the simple percentage-of-max-HR approach.
- Zone 1 — 50–60% HRR: Active recovery, easy walking, warm-up
- Zone 2 — 60–70% HRR: Aerobic base building, fat burning
- Zone 3 — 70–80% HRR: Improved aerobic capacity, tempo pace
- Zone 4 — 80–90% HRR: Anaerobic threshold training, race pace
- Zone 5 — 90–100% HRR: Maximum effort, sprint intervals
Zone 2 training has gained significant attention in 2026 for longevity and aerobic efficiency. It trains the mitochondria without accumulating excessive fatigue.
Frequently Asked Questions
How are heart rate zones calculated?
This tool uses the Karvonen (heart-rate-reserve) formula, which factors in your resting heart rate for more personalised zones than the simple max-HR method.
What is maximum heart rate?
Maximum heart rate is commonly estimated as 220 minus your age, though individual values vary. It is the upper limit used to define the zones.
What are the 5 heart rate zones?
Zone 1 (very light/recovery), Zone 2 (light/fat burn), Zone 3 (moderate/aerobic), Zone 4 (hard/anaerobic) and Zone 5 (maximum effort).
Which zone is best for fat burning?
Lower zones (roughly Zone 2) burn a higher percentage of fat, while higher zones burn more total calories. Most plans mix both.
Do I need a heart rate monitor?
A chest strap or wrist monitor makes it far easier to train within a target zone, but the calculator works from your age and resting heart rate alone.
Is this suitable for beginners?
Yes. Beginners usually spend most time in Zones 1–2. Consult a doctor before intense training if you have any health conditions.